Single crystal x-ray diffraction of lead magnesium niobate-lead titanate in the transmission mode

摘要

0.7Pb(Mg_(1/3)Nb_(2/3))O_3-0.3PbTiO_3 single crystals were examined by single crystal x-ray diffraction in the transmission mode, and a superlattice was revealed with a doubling of the unit cell in all three directions, giving a cell volume eight times that of a traditional perovskite unit cell. The significance of the superlattice peaks increased with poling, indicating a structural contribution to ordering. Lack of such observations by electron diffraction in the transmission electron microscope examinations suggests the presence of a bulk effect.